To Create a Spur Gear Pair
1. Click 
Gears. The Gear Pair Definition dialog box opens.
Gears. The Gear Pair Definition dialog box opens.2. Under Type, select Spur.
3. Enter the following information on the Gear1 tab:
◦ Select a rotational motion axis. A magenta arrow appears on the joint, indicating the positive direction for the axis. Use the right-hand rule to determine the direction of rotation.
The names of the rigid bodies connected by the joint appear in the Rigid Bodies area of the tab. By default, the first rigid body in the connection is called the Gear, the second rigid body the Carrier. To reverse the rigid body order, click 
. You can view the rigid body order associated with a given gear in the Mechanism Tree by clicking Gears in the Connections folder, and then clicking the arrow next to the name of the gear.
. You can view the rigid body order associated with a given gear in the Mechanism Tree by clicking Gears in the Connections folder, and then clicking the arrow next to the name of the gear.◦ Under Pitch Circle, type a value for the diameter of the pitch circle in the Diameter box.
◦ Next to Icon location, click 
and select a point, a vertex, a datum plane or a surface perpendicular to the axis for the location of the pitch circle icon. The default location is at the root of the Gear1 joint.
and select a point, a vertex, a datum plane or a surface perpendicular to the axis for the location of the pitch circle icon. The default location is at the root of the Gear1 joint.4. Enter the following information on the Gear2 tab:
◦ Select a rotational motion axis that is parallel to the Gear1 axis. A shaded arrow appears indicating the positive direction. To reverse the direction, click . The names of the rigid bodies connected by the joint appear in the Rigid Bodies area of the tab. By default, the first rigid body in the connection is the Gear, the second is the Carrier. To reverse the rigid body order, click .
. The names of the rigid bodies connected by the joint appear in the Rigid Bodies area of the tab. By default, the first rigid body in the connection is the Gear, the second is the Carrier. To reverse the rigid body order, click . | When the axes are in the same direction, a planetary gear pair is created by default. In this case the first gear should be external and the second should be internal. |
◦ The pitch diameter of Gear2 is automatically calculated to connect with the pitch diameter of Gear1. The pitch circle location of Gear2 is automatically calculated to match the location of the pitch circle location of Gear1.
When you press ENTER, two circles are displayed centered on the selected motion axis. These two circles are connected by smaller segments representing the helix angle. The line from the center of one circle to its circumference shows the zero-reference point of the motion axis.
The resultant gear is either internal or external, depending on axis direction.
5. On the Properties tab, choose a Gear Ratio type from the list. If you select Pitch circle diameter (default), you can still edit the value of the diameter for the Gear1 pitch circle on the Gear1 tab. If you select User defined, enter real number values for relative pitch circle diameters or enter the number of gear teeth for Gear1 and Gear2 under Gear Ratio. The diameters of the pitch circles on both tabs is automatically calculated.
6. Enter values for the Pressure Angle (default = 20°) and the Helix Angle of the gear connection. The helix angle is applied to Gear 1, and the corresponding helix angle on Gear 2 is automatically set to match the helix angle on Gear 1.
| | A positive helix angle indicates that the spiral is right-handed. |